Immediate post-operative prosthetic devices have been known to aid in the restoration of function of the dismembered limb since the 1960's. The loss of a lower extremity by amputation has profound physical and psychological consequences to the patient. Until recently, the amputation site was treated post-operatively with soft compressive dressings, nonremovable rigid dressings, or with a so-called removable rigid dressing which was made from a plaster or fiberglass cast. The reason it is considered removable is because it is pulled off the stump and then replaced after inspection. These devices allowed full weight-bearing through a temporary prosthesis after the wound had healed. Early mobilization of a patient after amputation is now generally accepted as an important part in amputation rehabilitation.
Early weight-bearing is extremely valuable in both the physical and psychological rehabilitation of the amputee. By resuming ambulation with partial or full weight-bearing at an early stage, postural reflexes can be maintained, while the residual stump may be readied for a definitive prosthetic fitting.
Many advantages are offered by fitting a prosthetic device immediately after amputation. These include early ambulation, more rapid healing of the amputation site, decreased post-operative pain and edema of the stump, shorter hospitalization times, earlier fitting of a definitive prosthesis and generally improved physical condition of the patient by preventing hypostatic pneumonia, phlebothrombosis, disuse weakness and psychological depression. The amputation team consisting of the surgeon, the physiatrist, the prosthetist and the physical therapist is aided by the immediate post-operative prosthetic device in the efficient treatment of the amputee.
In a historical perspective, as early as 1926, Le Mesurier found that a rigid dressing applied to the amputee stump immediately post-operatively initiated progressive ambulation as early as the condition of the patient permitted. Michael Berlemont of France initiated a second version of the rigid dressing for partial weight-bearing. This design was later modified by Marian Weiss of Poland for increased weight bearing. Ernest Burgess introduced the rigid dressing immediate post-surgical fitting into the United States in the 1960's. Dr. Burgess found that the closed wound of an amputation could be subjected to firm, even, pressures by use of a rigid dressing, which were carefully applied with relief for bony prominences, while attempting to avoid proximal restriction. His immediate post-surgical prosthetic devices were used on many amputation levels, including below the knee, knee disarticulation, above the knee, Syme and hip disarticulation.
However, in order to inspect the wound, the currently used prior art removable rigid dressings were merely pulled off the amputation stump, causing very great pain to the patient and generating so much friction as to traumatize the terminal surgical wound and the skin of the stump. Even though there is a felt pad between the stump and the rigid cast, the intense pain of removal and replacement discouraged patients from having their wounds inspected daily.
In addition, the prior art removable rigid dressing was applied on the operating table after the surgeon closed the amputation wound. The dressing was either a plaster cast or fiberglass. The plaster of paris reaction which occurs during the curing of the plaster or fiberglass cast generates a great deal of heat which is quite detrimental to the residual limb which already experiences compromised circulation. This is especially a problem when the amputation was performed for peripheral vascular disease.
The prior art removable rigid dressings were formed over the stump after the amputation operation. By their very nature, these rigid casts were non-adjustable and required frequent changes or entirely new casts as swelling of the stump decreased. As plaster and fiberglass casts must be custom made, they could not be reused or adjusted. The fact that they are non-adjustable means that a new cast was required when the swelling decreased to a point where the cast would have a sloppy, non-compressive fit over the stump.
Moreover, the Burgess technique requires extensive expertise for the rigid cast application, and does not allow the amputation site to be available for daily inspection. Consequently, a high incidence of stump complications became apparent, thereby requiring frequent removal of the rigid cast for inspections. The technique of Dr. Burgess was available only to patients in special medical centers where experienced prosthetists were available. As rehabilitation progresses, and the patients need to return to their physiatrists and prosthetists for continuing treatments, the immediate post-op device is used until the definitive prosthetic device is fitted.
Early attempts to solve these drawbacks included prefabricated pneumatic or plastic prosthetic devices, pneumatic air splints such as the one introduced by Morris Kerstein, and metal pylons. Although these remedies provided ease of application with ready access to the amputation site, there is no ability to flex at the knee joint, and only limited diffuse weight-bearing was possible. The air splint did not provide the capability for full weight-bearing, due to its very nature. The use of metal pylons is restricted as they are constructed of copper tubing fabricated by splitting the copper tube at one end to provide a tripod base. This base is secured to the end of a well-molded plaster rigid casting and applies pressure directly on the posterior end of the stump. Because pressure is applied directly onto the healing stump, the patients experience pain. Of the previous immediate post-operative devices, such as the pneumatic or plastic prostheses or metal pylons, none were able to provide full weight bearing. Rather, they only permitted limited weight bearing through the painful and swollen amputation stump with unhealed surgical wound in the early post-operative period.
Consequently, there is a need for an inexpensive, easy-to-fit device which is prefabricated and adjustable for the many different height and orientation requirements of individual patients. It would be advantageous to have one prosthetic device to be used for above the knee, below the knee and knee disarticulation amputations, as well as one that would allow full weight-bearing within the first few days after the amputation surgery by bypassing weight-bearing across painful and swollen stumps with a fresh or unhealed surgical wound without compromise of wound healing, skin integrity or circulation of the residual limb.
Furthermore, there is a need for a rigid dressing to be used with such a prosthetic device to reduce the incidence of distal edema, to encourage fast stump shrinkage without a cast change, to immobilize soft tissue to reduce pain and facilitate wound healing, and to prevent trauma to the stump. In addition, there is a need for a rigid dressing that is easily and painlessly removable to permit frequent observation and one which is furthermore fast and easy to apply and remove.
Accordingly, it is the primary aim of the present invention to provide a prosthetic device and rigid dressing assembly for lower limb amputation patients which is inexpensive, easy to apply without expert prosthetists, reusable, and easy to fit. The present invention is designed to provide a prosthetic device which allows for full ischial weight-bearing without compromising the wound healing.